Transfer of data over a network medium is typically accomplished as a sequence of frames. The format of these frames over a physical medium usually comprises a series of a preamble field, an optional frame specification field, a payload or data field, and an inter-frame gap. Each of the fields of the frame format has a particular purpose. The preamble may be used to synchronize the transmitter and receiver. An optional frame specification may convey information such as the coding method or length of the frame, and to reserve the medium. The inter-frame gap or space may be used to allow for propagation and receiver processing delays. The inter-frame gap may also be included to allow for transmitter initialization and processing delays when the transmitted frame may result in a transmitted response from the recipient.
In various protocols, some fields of a frame format may be required, and may be transmitted at a fixed data transmission rate, to enable all receivers to be able to receive network information related to occupancy of the shared medium. Those fields may, therefore, occupy a fixed amount (i.e., fixed time period) of the shared transmission medium, despite increases in the rate of transmission of other portions. Efforts to increase the rate of data transfer are hampered by such fixed duration protocol elements. As the frame data transmission rate increases, the time taken to transmit the payload or data fields shrinks, while the time occupied by the fixed rate fields does not. This causes the medium usage efficiency to fall, yielding diminishing returns from increasing data transmission rates.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of ordinary skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.